Now, Bit Torrents are based on sharing. The last thing you want is some anti-piracy agency obtaining your IP address. Use PeerGuardian 2 to filter out harmful IP's trying to connect to you. Phoenix Labs » PeerGuardian 2

For a DVD burner, that all depends on your current system and needs. Do you have an extra drive bay? Is your motherboard SATA or PATA? Do you want an external USB recorder?